My heart sings. It does. In 1980 there was not one openly gay person in my 1600-student high school. In 1989, Denmark was the first nation to introduce civil unions (not even marriage!), and I thought, That will never, never, never happen here. I doubt 20-somethings today can even comprehend what that world was like. And twenty years from now it will boggle kids’ minds to imagine a presidential election with no serious candidate standing up for marriage equality. Because that time is over!

here’s where Obama’s shift today means everything: He went on television, with all the power and resonance of his office, to give gay marriage his clear and firm endorsement. His words will play everywhere, and everyone will understand them. That wasn’t true of Eric Holder’s lawyerly letter about DOMA, however important it has been. The positions that the government takes in court matter. But the gift President Obama gave the country today matters so much more.

The statement changes everything because it locks in place for another generation the Brand ID of Democrats as the party of cultural modernity. This Brand ID fits uneasily upon the Democrats, for they are also the party of ethnic minorities and recent immigrants. With the president's statement, however, the modernists have gained the clear upper hand. Meanwhile on the Republican side of aisle, the cultural modernists keep losing. For all that people talk about the ascendancy of the Koch Brothers within the GOP, I'd venture that Charles and David feel about same-sex marriage almost exactly as President Obama does. Yet on this one, they lose.

Obama looked like a phony and a coward each day he fudged this issue, and that his taking a strong and principled stand will have a halo effect on his leadership in general, including among voters who are ambivalent about gay marriage or opposed to it. Just look at Andrew Cuomo, whose approval rating remains high upstate and among Republicans, not just among liberals in New York City and its suburbs.

[T]he pressure continuously applied on Obama by some gay groups, most gay activists, and (especially) rich gay funders undoubtedly played a significant role in all of these successes. As David Sirota explained today, this demonstrates why it is so vital to always apply critical pressure even to politicians one likes and supports, and conversely, it demonstrates why it is so foolish and irresponsible to devote oneself with uncritical, blind adoration to a politician, whether in an election year or any other time (unconditional allegiance is the surest way to render one’s beliefs and agenda irrelevant).

Romney might make gains among culturally conservative opponents of same-sex marriage in Ohio and other Midwestern states, yet GOP campaigning on cultural issues might strengthen the president’s position with college-educated upper-middle-class voters. Drawing a sharp contrast on social issues reinforces the president’s claim to be the candidate of “enlightenment and progress” against “reaction, bigotry, and hate.” This is the kind of campaign — focused on broad generalities rather than detailed questions concerning the state of the economy, debt and deficits, etc. — that the president wants to run, and it is easy to see why.

Obama has been less of a leader than a follower on the great civil-rights issue of our time. Now he has a chance to lead—to use his bully pulpit and his eloquence to reshape the discussion over marriage equality. … Let’s hope this is the start of something, and not just the belated end of an evolution.